NEA’s research product and solution strategies for commercial applications have been widely disseminated in a book, a book chapter, monographs, archival publications, and conference papers. The newest and most comprehensive treatment is in Process Chemistry of Coal Utilization: Impacts of Coal Quality and Operating Conditions (ISBN-978-0-12-818713-5) published by Elsevier and available on Elsevier.com, Amazon.com, and other websites for technical books. This book presents reaction mechanisms with predictive capabilities for any coal under the operating domains of all major coal utilization technologies, including pulverized coal furnaces, entrained flow gasifiers, static and circulating fluidized bed combustors, fluidized bed gasifiers, oxyfuel combustors, and transport gasifiers. The detailed mechanisms are used to specify much simpler rate expressions for implementation in CFD simulations. Readers will benefit from the abundance of lab datasets, which illustrate how a particular operating condition affects a specific coal-based reaction system. For example, how increasing pressure affects the partitioning of coal into volatiles and char; or how changing from subbituminous to medium volatile bituminous coal changes the distribution of products in a certain reaction system. This book develops a comprehensive framework for coal conversion chemistry that clearly delineates the various stages, which enables managers to tailor their testing and simulation work to effectively characterize and solve their problems.

The most comprehensive source for NEA’s reaction mechanisms on mercury transformations is a chapter entitled, “Predicting Hg Emissions Rates With Device-Level Models and Reaction Mechanisms” that appears in Mercury Emissions Control for Coal-Derived Gas Streams, ISBN: 978-3-527-32949-6, Eds. E Granite, HW Pennline, CL Senior, Wiley, 2012. Collectively, the reaction mechanisms described in this chapter cover all the most common fuels, firing configurations, and gas cleaning configurations, and enable accurate estimates for Hg emissions rates from virtually any commercial power plant. In-flight Hg transformations are determined by halogen concentrations, the halogenated surface area on unburned carbon and carbon sorbents, the type of particle collection device, and, in ACI applications, the ACI concentration. ACI with untreated carbon sorbents mitigates the inherent variations in chlorinated surface area among different coals, but does not necessarily eliminate the halogen dependence. This limitation is clearly seen in the much-lower-than expected asymptotic Hg removals for ACI with many low-rank coals. ACI with brominated carbon completely circumvents these limitations. Unfortunately, even this “universal” solution may be diminished by SO₃ inhibition. The Hg⁰ oxidation performance of SCRs is no less variable than the in-flight transformations, because SCR design specifications and operating conditions are at least as important as the halogen concentrations. The essential feature is that NH₃ adsorption inhibits the adsorption of the species involved with Hg⁰ oxidation. Factors that enhance surface halogenation, such as higher inlet halogen concentrations and lower NH₃/NO ratios, also promote Hg⁰ oxidation. Br species dramatically accelerate Hg⁰ oxidation rates on some catalysts by as much as a factor of 40 compared to the rates for Cl species.

NEA has published about 250 journal articles and conference papers on numerous topics pertaining to solid fuel utilization. One long-standing interest has been the release of NO_X, particulates, and polynuclear aromatic compounds during pulverized fuel combustion and, more generally, solid fuel kinetics for devolatilization, combustion, and gasification. Another main interest has been transformations in combustors of minerals, alkali compounds, and trace metals, including comprehensive mechanisms for Hg and Se emissions from coal-fired gas cleaning systems; alkali vapor emissions from pressurized fluidized bed combustors; and corrosion potentials due to alkali chlorides in slags. A third interest has been catalyst deactivation during hydrothermal treatment of residual petroleum fractions, and during flue gas cleaning in utility SCRs. A fourth has been catalysis for combustion, including predictive mechanisms for multipollutant (NO_X, SO₂, Hg⁰) conversion across SCR catalysts, the thermal and chemical behavior of catalytic converters, and thermal shock issues in catalytic combustors for natural gas. The easiest way to obtain copies of NEA’s papers on these topics is through ResearchGate.net under the name, “Stephen Niksa.” A more complete bibliography appears on Google Scholar under the same name. You can also request papers on your topics of interest via email to niksaenergy@gmail.com.